Description (CNA)
In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_tables: do not defer rule destruction via call_rcu nf_tables_chain_destroy can sleep, it can't be used from call_rcu callbacks. Moreover, nf_tables_rule_release() is only safe for error unwinding, while transaction mutex is held and the to-be-desroyed rule was not exposed to either dataplane or dumps, as it deactives+frees without the required synchronize_rcu() in-between. nft_rule_expr_deactivate() callbacks will change ->use counters of other chains/sets, see e.g. nft_lookup .deactivate callback, these must be serialized via transaction mutex. Also add a few lockdep asserts to make this more explicit. Calling synchronize_rcu() isn't ideal, but fixing this without is hard and way more intrusive. As-is, we can get: WARNING: .. net/netfilter/nf_tables_api.c:5515 nft_set_destroy+0x.. Workqueue: events nf_tables_trans_destroy_work RIP: 0010:nft_set_destroy+0x3fe/0x5c0 Call Trace: <TASK> nf_tables_trans_destroy_work+0x6b7/0xad0 process_one_work+0x64a/0xce0 worker_thread+0x613/0x10d0 In case the synchronize_rcu becomes an issue, we can explore alternatives. One way would be to allocate nft_trans_rule objects + one nft_trans_chain object, deactivate the rules + the chain and then defer the freeing to the nft destroy workqueue. We'd still need to keep the synchronize_rcu path as a fallback to handle -ENOMEM corner cases though.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected 9eee6097ffb26cdd2adb988c0d378fa0d650c737 before 5146c27b2780aac59876a887a5f4e793b8949862; affected 558f503f707f481bbf40efa74a938b8021df841d before 2991dc357a28b61c13ed1f7b59e9251e2b4562fb; affected a394c160d57f4b083bd904a22802f6fb7f5b3cea before b8d8f53e1858178882b881b8c09f94ef0e83bf76; affected e6c32a64d61184c2bdf89442b3d31ef530afba34 before b0f013bebf94fe7ae75e5a53be2f2bd1cc1841e3; affected bfd05c68e4c6320304e9f371ffa356b6e4b9cc53 before 27f0574253f6c24c8ee4e3f0a685b75ed3a256ed; affected c03d278fdf35e73dd0ec543b9b556876b9d9a8dc before 7cf0bd232b565d9852cb25fd094f77254773e048; affected c03d278fdf35e73dd0ec543b9b556876b9d9a8dc before b04df3da1b5c6f6dc7cdccc37941740c078c4043; affected cb401e5799e0acacb405f2128097e9c4ccf82f8a; affected 6.6.61 before 6.6.67; affected 6.11.8 before 6.12 |
| Linux / Linux | affected 6.12; unaffected 0 before 6.12; unaffected 6.6.67 through 6.6.*; unaffected 6.12.6 through 6.12.*; unaffected 6.13 through * |
CWE
No CWE identifiers supplied.
References
- https://git.kernel.org/stable/c/5146c27b2780aac59876a887a5f4e793b8949862
- https://git.kernel.org/stable/c/2991dc357a28b61c13ed1f7b59e9251e2b4562fb
- https://git.kernel.org/stable/c/b8d8f53e1858178882b881b8c09f94ef0e83bf76
- https://git.kernel.org/stable/c/b0f013bebf94fe7ae75e5a53be2f2bd1cc1841e3
- https://git.kernel.org/stable/c/27f0574253f6c24c8ee4e3f0a685b75ed3a256ed
- https://git.kernel.org/stable/c/7cf0bd232b565d9852cb25fd094f77254773e048
- https://git.kernel.org/stable/c/b04df3da1b5c6f6dc7cdccc37941740c078c4043